Various systems have been proposed to prevent the bursting of water pipes when water freezes and expands in them. Thus, externally connected branches or reservoirs have been used with compressible compartments outside the water pipes such as in Robison U.S. Pat. No. 1,672,393, June 5, 1928. These require extra piping and plumbing which may not fit in crowded spaces and which is very expensive. Specially constructed compressible air filled compartments within the water flow path such as provided in Noland U.S. Pat. No. 3,480,027, Nov. 25, 1969 or Wadleigh U.S. Pat. No. 4,649,959, Mar. 17, 1987 have the same objections and are subject to leakage and fatigue.
Various sealed or solid compressible bodies have been made for insertion within water pipes, such as in Tickel U.S. Pat. No. 2,360,596, Oct. 17, 1944, but these are subject to movement out of position with the flow of water through the pipe. Thus, Firey, U.S. Pat. No. 596,062, Dec. 28, 1897 has provided compressible rubber inserts of fixed length with flanges for holding them in place in the center of the pipe. These cannot be used around bends, such as found near outside faucets where protection is critical and where pipe dimensions vary because of faucets and couplings. Rubber deteriorates with age and cannot provide permanent protection.
Devices which move within the pipe such as in Reed U.S. Pat. No. 4,3211,908, Mar. 30, 1982 or multiple piece assemblies critical to assemble locate and install as found in the Craig-Hallam British publication 2,176,565A, Dec. 31, 1986 are complex and unsatisfactory because of critical installation, fixing in place and possiblity of failure in action.
It is therefore an object of this invention to provide an inexpensive and easy to install versatile system operable under various conditions that will stay in place and overcome the aforesaid deficiencies of the prior art.